<script type='text/javascript'>
//<![CDATA[
var startTime = new Date();
function showElapsedTime() {
var testSiteUrl = location.href;;
var testSiteString = String(testSiteUrl).slice(testSiteUrl.indexOf("www"));
var endTime = new Date();
var elapsedTime = Number(endTime-startTime);
var browser=navigator.userAgent;
var platform=navigator.platform;
var msgString = "Время загрузки " + Number(elapsedTime/1000) + " секунд (" + elapsedTime + " ms)<br/><span>Браузер " + browser + "</span>";
document.getElementById("vremia").innerHTML = msgString;
}
onload=function() {showElapsedTime();}
//]]>
</script>

<div id="vremia">Загрузка ...</div>